Safety device for aeroplanes.



B. ULFERTS..

SAFETY DEVICE FOR AEROPLANES.

APPLICATION FILED JUNE l0, 1914.

Patented Apr.. 13, 1915.

2 SHEETS-SHEET 1.

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i /fff" B. ULFERTS.

SAFETY DEVICE EUR AEROPLANES.

APPLICATION FILED JUNE I0. 1914.

2 SHEETS-SHEET 2.

Patented Apr. 13, 1915.

BEND ULFERTS, F LAKEFIELD, MINNESOTA.

SAFETY DEVICE FOR AEROPLANES.

Maasai..

Specification of Letters Patent. Pajtmtjal Apu. f3, 1915.

Application led .Tune 10, 1914., Serial No. 844,280.:

T0 all whom it may concern: I

Be it known that ll, BEHREND Unrnn'rs, a citizen of the United States, residing at Lakefield, inl the county of 'Jackson and State of Minnesota, have invented certain new anduseful Improvements in Safety Devices for vAeroplanes, of which the following is a specification.

My invention relates to a safety device for aeroplanes, designed especially foruse in preventing downward and forward tipping and loss of longitudinal stability in the event of the machine in'its course of travel encountering an air hole or rarefied area of air, the object of theinvention being to provide a safety vane which may be thrown into action under the conditions mentioned to prevent the machine from tipping beyond a certain degree and to restore the machine to a normal state of equilibrium or .stability A further object of the invention is tol provide a safety vane which is normally held close down upon the rarefaction surl face cf a main supporting plane of the machineby restraining means under control. of the. aviator, upon the release of which restraining means, which also serves as a means for returning the vane to ,a normal condition under operation, the vane will be vautomatically projected for safety action.

porting surface of a biplane at one end of the machine, showing the application of the invention thereto; Fig. 2 is a vertical longitudinal section through the same; Fig. 3 is a top plan view of the upper supporting plane, showing the safety vane in normal position; Fig.v t `is an enlarged detail section throughthe upper supporting plane,

showing the safety vane projected when the machine tilts downwardly and forwardly; and Fig. 5 is a detail view of one of the guide members.

lin the present instance ll have shown the application of my invention to a biplane structure, although it is to be understood that it may be employed inA connection with aeroplanes of other types,'and also in connection with dirigible balloons and airships generally.

,R ferring to the drawings, 1 and 2 designate the upperl and lower supporting planes connected inthe usual'manner by the stanclr ions 3; and 4 `designates the aviators seat which may b e mounted upon the framework of the lower plane, as in some machine structures.

The safety vane 5 ishinged to the upper or rarefaction surface of the upper plane 1, as indicated at 6, and is adapted to normally lie folded down upon said surface, so as to avoid setting up` any added head resistance when the machine is in flight. The vane is coextensive in length with the plane l and of a width approximately` one-thirdof the width of the plane. ln practice, the vane may cover the upper portion of the plane 1 from a point coincident with its leading edgeto a point somewhat in rear of its camber line,.the vane itself being of a sucient area for ya safety supporting action, as

hereinafter described.

The vane 5 is adapted to be automatically projected upwardly by means of a series of impelling springs 7, preferably ofleaf form, fixed at one en d to the plane and arranged to fold within receiving recesses 8 in said plane, said springs being held folded under the pressure of the vane when the latter is retained in folded position, and operating when the vane is released to project the vane upward sufficiently to catch the force Aof the wind, underthe pressure of which the vane will be moved upwardly and rearwardly to an operative position, as shown in Fig. 4.

To the forward or free edge of the vane are attached the upperends of controlling cords or cables 9 which'pass downwardly through guides 10 supported by the front stanchions 3 and are wound at their lower ends around drums 11 on a shaft 12 journaled in suitable bearings upon the forward portion of the lower plane 2. Coil springs 13 surround said 'cables below the guides 10 and between the (same and suitable abutments 11i-on the cables, said springs serving to maintain the cables in a normal taut condition and to resist upward movement of the vane 5 until said vane is positively released and forced upward by the spring 7 and the pressure of the air. Fixed to the shaft 12 is a ratchet wheel 15 engaged by a pivoted locking pawl 16 coupled by a link 17 with a releasing lever 18 carrying a spring actuated dog 19 to engage a rack 20. The pawl 16 is normally in engagement with the ratchet wheel and operates in conjunction with the springs 13 to hold the vane 5 in a folded or-inoperative position, but it will be evident that in the event of the downward and forward tipping of the machine to a dangerous degree the operator, by manipulation of the lever 18, may retract the pawl 16 to allow the cables 9 to rewind over the drums 11, thus releasing the vane 5 for projection bythe actuating springs 7. The series of springs 7 arelstronger than the series of springs 13, and hence upon the release of the cables will project the vane 5 upward to a determined degree against the resistance of the springs 13, the vane 5 being thus projected into the path of the wind under the pressure of which it will move upwardly and rearwardly to the position shown in Fig. 4, in which position said vane acts as an auxiliary surface exposed to the pressure of the air at such an angle that the air pressure acting thereon will elevate the forward portion of the machine and correct its downward tilting tendency and lreturn the machine to a normal state of longitudinal balance or equilibrium. The springs 13 act as cushioning or checking springs to prevent the vane 5 from being forced up too violently by wind pressure, thus preventing possible damage to the vane as will be readily understood.

1t will be evident from the foregoing description that by means of my improved safety device the aviator may at any time in the event of danger, due to the downward and forward tilting of the machine to a dangerous degree, prevent loss of the longitudinal balance and return the machine to a normal balanced condition by simply manipulating the controlling lever to effect the automatic projection of the safety vane to a working position. Any suitable means for actuating the shaft to rewind the cables on the drums and return the vane to normal position after action may be employed.

While the supporting surface is shown as imperforate, it is to be understood that the portion thereof disposed beneath the safety flap maybe perforate and normally closed by said fiap, in which event the flap will form a coinplemental part of the supporting surface, as will be readily understood.

Having thus described my invention, I claim:

1. A flying machine having a supporting surface, a safety vane pivoted at its rear edge upon the upper side of-said surface for upward and rearward movement to an an gle of incidence, means for releasing the holding means, and means for establishing a yielding resistance through said holding means to the movement of the vane to an acting position.

2. A flying machine having a supporting surface, a safety vane pivoted at its rear edge to the forward portion of said surface to fold down upon said surface and to swing upwardly and rearwardly to an angle of incidence, means for holding the vane inactive, springs upon said supporting surface for throwing the same into action when released, means for releasingy the holding means, and means for. establishing'a yielding resistance through said holding means to the movement ofthe vane to an `acting position.

3. A iying machine having a supporting surface, a safety vane pivotally mounted upon said surface to fold downwardly thereon and -to swing upwardly and rearwardly to an acting angle of incidence, means for normally holding said vane folded and inactive, means for releasing the holding means, and means for establishing a yielding resistance through said holding means to the movement of the vane to an acting position.

4. A iying machine having a supporting surface, a pivoted safety vane arranged to fold downwardly thereon to an inoperative position and to swing upwardly and rearwardly to an lactive angle of incidence, springs for projecting said vane, cables for normally holding said vane inactive and for releasing ,it for action, retaining and re- -leasing means associated with said cables, and cushioning means associated with saidl cables, to retard the opening movement of the vane.

5. A flying machine having a supporting surface, a pivoted safety vane,a shaft, drums upon said shaft, cables connecting the drums with the vane, whereby said vane may be held inactive and released for action, means for locking and releasing the said shaft, and means associated with the cables for opposing a. yielding resistance to the opening movement of the vane.

6. A iying machine having a supporting surface, a pivotedsafety vane, springs for projecting said vane, av shaft, drums upon the shaft, cables wound upon the drums and connected with the vane, whereby the vane may be held inoperative and released for operation, locking and releasing means acting on said shaft, and springs acting on the cables to establish a yielding resistance to the opening movement of the vane.

7. A flying machine having a supporting surface, a safety vane pivotally mounted upon said surface to folddownwardly therementor on and to Swing npwnrdly vond rearwardly ][n testimony whereof I a my signoto on etigmongle oid incideteiezl ean fior ture in presence of two Witnesses. norma o n son vane o e nn 1n- 1. native, ineens r releasing the holding BLEND ULFERTS t means, and means for establishing n yield- Witnesses: v

ing resistance to the movement of the vaine @r'ro Wnnrns.. to nn noting position. v en L. ERICKSON. 

